1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Backlight driver for Dialog Semiconductor DA9030/DA9034
4 *
5 * Copyright (C) 2008 Compulab, Ltd.
6 * Mike Rapoport <mike@compulab.co.il>
7 *
8 * Copyright (C) 2006-2008 Marvell International Ltd.
9 * Eric Miao <eric.miao@marvell.com>
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/platform_device.h>
15 #include <linux/backlight.h>
16 #include <linux/mfd/da903x.h>
17 #include <linux/slab.h>
18 #include <linux/module.h>
19
20 #define DA9030_WLED_CONTROL 0x25
21 #define DA9030_WLED_CP_EN (1 << 6)
22 #define DA9030_WLED_TRIM(x) ((x) & 0x7)
23
24 #define DA9034_WLED_CONTROL1 0x3C
25 #define DA9034_WLED_CONTROL2 0x3D
26 #define DA9034_WLED_ISET(x) ((x) & 0x1f)
27
28 #define DA9034_WLED_BOOST_EN (1 << 5)
29
30 #define DA9030_MAX_BRIGHTNESS 7
31 #define DA9034_MAX_BRIGHTNESS 0x7f
32
33 struct da903x_backlight_data {
34 struct device *da903x_dev;
35 int id;
36 int current_brightness;
37 };
38
da903x_backlight_set(struct backlight_device * bl,int brightness)39 static int da903x_backlight_set(struct backlight_device *bl, int brightness)
40 {
41 struct da903x_backlight_data *data = bl_get_data(bl);
42 struct device *dev = data->da903x_dev;
43 uint8_t val;
44 int ret = 0;
45
46 switch (data->id) {
47 case DA9034_ID_WLED:
48 ret = da903x_update(dev, DA9034_WLED_CONTROL1,
49 brightness, 0x7f);
50 if (ret)
51 return ret;
52
53 if (data->current_brightness && brightness == 0)
54 ret = da903x_clr_bits(dev,
55 DA9034_WLED_CONTROL2,
56 DA9034_WLED_BOOST_EN);
57
58 if (data->current_brightness == 0 && brightness)
59 ret = da903x_set_bits(dev,
60 DA9034_WLED_CONTROL2,
61 DA9034_WLED_BOOST_EN);
62 break;
63 case DA9030_ID_WLED:
64 val = DA9030_WLED_TRIM(brightness);
65 val |= brightness ? DA9030_WLED_CP_EN : 0;
66 ret = da903x_write(dev, DA9030_WLED_CONTROL, val);
67 break;
68 }
69
70 if (ret)
71 return ret;
72
73 data->current_brightness = brightness;
74 return 0;
75 }
76
da903x_backlight_update_status(struct backlight_device * bl)77 static int da903x_backlight_update_status(struct backlight_device *bl)
78 {
79 return da903x_backlight_set(bl, backlight_get_brightness(bl));
80 }
81
da903x_backlight_get_brightness(struct backlight_device * bl)82 static int da903x_backlight_get_brightness(struct backlight_device *bl)
83 {
84 struct da903x_backlight_data *data = bl_get_data(bl);
85
86 return data->current_brightness;
87 }
88
89 static const struct backlight_ops da903x_backlight_ops = {
90 .options = BL_CORE_SUSPENDRESUME,
91 .update_status = da903x_backlight_update_status,
92 .get_brightness = da903x_backlight_get_brightness,
93 };
94
da903x_backlight_probe(struct platform_device * pdev)95 static int da903x_backlight_probe(struct platform_device *pdev)
96 {
97 struct da9034_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
98 struct da903x_backlight_data *data;
99 struct backlight_device *bl;
100 struct backlight_properties props;
101 int max_brightness;
102
103 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
104 if (data == NULL)
105 return -ENOMEM;
106
107 switch (pdev->id) {
108 case DA9030_ID_WLED:
109 max_brightness = DA9030_MAX_BRIGHTNESS;
110 break;
111 case DA9034_ID_WLED:
112 max_brightness = DA9034_MAX_BRIGHTNESS;
113 break;
114 default:
115 dev_err(&pdev->dev, "invalid backlight device ID(%d)\n",
116 pdev->id);
117 return -EINVAL;
118 }
119
120 data->id = pdev->id;
121 data->da903x_dev = pdev->dev.parent;
122 data->current_brightness = 0;
123
124 /* adjust the WLED output current */
125 if (pdata)
126 da903x_write(data->da903x_dev, DA9034_WLED_CONTROL2,
127 DA9034_WLED_ISET(pdata->output_current));
128
129 memset(&props, 0, sizeof(props));
130 props.type = BACKLIGHT_RAW;
131 props.max_brightness = max_brightness;
132 bl = devm_backlight_device_register(&pdev->dev, pdev->name,
133 data->da903x_dev, data,
134 &da903x_backlight_ops, &props);
135 if (IS_ERR(bl)) {
136 dev_err(&pdev->dev, "failed to register backlight\n");
137 return PTR_ERR(bl);
138 }
139
140 bl->props.brightness = max_brightness;
141
142 platform_set_drvdata(pdev, bl);
143 backlight_update_status(bl);
144 return 0;
145 }
146
147 static struct platform_driver da903x_backlight_driver = {
148 .driver = {
149 .name = "da903x-backlight",
150 },
151 .probe = da903x_backlight_probe,
152 };
153
154 module_platform_driver(da903x_backlight_driver);
155
156 MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034");
157 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
158 MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
159 MODULE_LICENSE("GPL");
160 MODULE_ALIAS("platform:da903x-backlight");
161